CN116412951A

CN116412951A - Pressure detection method and device for expansion tank of closed circulation system

Info

Publication number: CN116412951A
Application number: CN202111644705.3A
Authority: CN
Inventors: 刘军卫; 王丁会
Original assignee: Beijing Goldwind Science and Creation Windpower Equipment Co Ltd
Current assignee: Beijing Goldwind Science and Creation Windpower Equipment Co Ltd
Priority date: 2021-12-29
Filing date: 2021-12-29
Publication date: 2023-07-11

Abstract

The application discloses a pressure detection method and a pressure detection device for an expansion tank of a closed circulation system, wherein the pressure detection method in the embodiment of the application comprises the steps of obtaining standard pressure P of gas of the expansion tank in a standard state ₀ Standard volume V ₀ Standard temperature T ₀ The method comprises the steps of carrying out a first treatment on the surface of the Acquiring a first pressure P of gas in an expansion tank under a state to be detected ₁ First temperature T ₁ The method comprises the steps of carrying out a first treatment on the surface of the Controlling the conduction of a liquid discharge pipeline of the expansion tank under the state to be tested; acquiring the volume of liquid discharged by the expansion tank, and changing the expansion tank into a transitional state when the volume of the liquid discharged is Vw; obtaining a second pressure P of the gas in the expansion tank in the transitional state ₂ The method comprises the steps of carrying out a first treatment on the surface of the According to the first pressure P ₁ Second pressure P ₂ First temperature T ₁ Volume of liquid discharged V _W Standard pressure P ₀ Standard volume V ₀ Standard temperature T ₀ Determining a first standard pressure P of the gas under the state to be measured _1t . The monitoring method provided by the embodiment of the application can test the gas in the expansion tankThe pressure intensity, the operation method is simple, and the detection efficiency is high.

Description

Pressure detection method and device for expansion tank of closed circulation system

Technical Field

The application relates to the field of cooling equipment, in particular to a pressure detection method and device for an expansion tank of a closed circulation system and a wind generating set.

Background

In the operation process of large-scale electronic equipment, a large amount of heat is generated, and a circulation system is generally required to exchange heat for the large-scale electronic equipment, so that the temperature is reduced. Or when the temperature is too low, a circulation system is required to heat the water to ensure the normal operation of the water. At present, a closed circulating cooling system using a liquid medium as a cooling medium is increasingly widely used, and the device brings the cooling medium into an electronic element radiator through a water pump to exchange heat so as to reduce the temperature of the electronic element. However, the volume of the cooling medium expands or contracts with a change in temperature, and thus a pressure stabilizing device needs to be connected to the circulation system.

The existing pressure stabilizing device generally comprises an expansion tank, wherein the expansion tank is provided with two closed chambers respectively used for containing a medium and pressure maintaining gas, and the volume of the pressure maintaining gas is possibly changed in the operation process of the expansion tank, so that the pressure maintaining gas needs to be detected to keep the standard pressure when leaving a factory.

Disclosure of Invention

The embodiment of the application provides a pressure detection method and device for an expansion tank of a closed circulation system and a wind generating set, wherein the pressure detection method and device can be used for testing the pressure of gas in the expansion tank, and is simple in operation method and high in detection efficiency.

In a first aspect, an embodiment of the present invention provides a pressure detection method for an expansion tank of a closed circulation system, where liquid and gas are stored in the expansion tank under a state to be detected, the pressure detection method includes: obtaining standard pressure P of expansion tank gas under standard state ₀ Standard volume V ₀ Standard temperature T ₀ The method comprises the steps of carrying out a first treatment on the surface of the Acquiring a first pressure P of gas in an expansion tank under a state to be detected ₁ First temperature T ₁ The method comprises the steps of carrying out a first treatment on the surface of the Controlling the conduction of a liquid discharge pipeline of the expansion tank under the state to be tested; acquiring the volume of liquid discharged by the expansion tank, and controlling the liquid discharge pipeline to be closed when the volume of the liquid discharged is Vw, so that the expansion tank is in a transitional state; obtaining a second pressure P of the gas in the expansion tank in the transitional state ₂ The method comprises the steps of carrying out a first treatment on the surface of the According to the first pressure P ₁ Second pressure P ₂ First temperature T ₁ Volume of liquid discharged V _W Standard pressure P ₀ Standard volume V ₀ Standard temperature T ₀ Determining a first standard pressure P of the gas under the state to be measured _1t 。

According to one aspect of the embodiment of the present invention, the gas volume difference Vq between the state to be measured and the transition state in the expansion tank is equal to the discharged liquid volume Vw.

According to one aspect of an embodiment of the invention, according to the first pressure P ₁ Second pressure P ₂ First temperature T ₁ Volume of liquid discharged V _W Standard pressure P ₀ Standard volume V ₀ Standard temperature T ₀ Acquiring a first standard pressure P of gas in an expansion tank under a state to be detected _1t Comprising: according to the first pressure P ₁ Second pressure P ₂ Volume of liquid discharged V _W Acquiring a first gas volume V of the gas to be detected ₁ The method comprises the steps of carrying out a first treatment on the surface of the According to the first gas volume V ₁ First temperature T ₁ Standard pressure P ₀ Volume of standard gas V ₀ Standard temperature T ₀ Acquiring a first standard pressure P of gas in a state to be detected _1t 。

According to one aspect of an embodiment of the invention, according to the first pressure P ₁ Second pressure P ₂ Volume of liquid discharged V _W Calculating the first gas volume V of the expansion tank under the state to be measured ₁ Comprising determining the first gas volume V by ₁ ，

According to one aspect of an embodiment of the invention, according to the first gas volume V ₁ Standard pressure P ₀ Standard gas volume V ₀ Acquiring a first standard pressure P of an expansion tank under a state to be detected _1t Comprising determining a first standard pressure P by _1t ,

According to an aspect of the embodiment of the present invention, further comprising: controlling the conduction of the fluid supplementing pipeline of the expansion tank to connect the bodyInjecting the liquid with the product Vw into an expansion tank; according to the first standard pressure P _1t First pressure P ₁ A differential pressure Pw is obtained, wherein pw= |p ₁ -P _1t I (I); the expansion tank is replenished with gas or exhausted with gas according to the pressure difference Pw.

According to one aspect of an embodiment of the invention, replenishing or venting gas into the expansion tank according to the pressure differential Pw comprises: acquiring the allowable deviation delta P of the expansion tank; determining whether the pressure difference Pw exceeds the allowable deviation ΔP, where Pw > ΔP, and P ₁ ＞P _1t Under the condition of +delta P, the gas transmission pipeline of the expansion tank is controlled to be conducted, so that the gas in the expansion tank is discharged until the pressure in the expansion tank reaches Pw less than or equal to delta P; or at Pw > ΔP, and P ₁ ＜P _1t And under the condition of delta P, controlling the conduction of a gas pipeline of the expansion tank, and supplementing gas into the expansion tank until the pressure in the expansion tank reaches Pw less than or equal to delta P.

According to an aspect of the embodiment of the present invention, before the step of obtaining the first pressure P1 of the gas in the expansion tank under the state to be measured, the method further includes: and controlling the liquid supplementing pipeline, the liquid discharging pipeline and the gas conveying pipeline of the expansion tank to be closed under the state to be detected.

According to one aspect of the embodiment of the invention, the first temperature T of the gas in the expansion tank under the state to be detected is obtained ₁ Comprising: acquiring the liquid temperature Tq flowing out of the expansion tank under the state to be detected; acquiring the ambient temperature Tg of the environment where the expansion tank is located under the state to be detected; according to the calculation formula T ₁ = (tq+tg)/2, obtaining a first temperature T of gas in the expansion tank in a state to be measured ₁ 。

In a second aspect, an embodiment of the present invention proposes a pressure detection device for an expansion tank of a closed circulation system, for implementing the pressure detection method in the above embodiment, the pressure detection device comprising: the liquid storage device comprises a liquid discharge pipeline, a liquid storage tank and a first switch valve, wherein two ends of the liquid discharge pipeline are respectively connected with a liquid inlet of the liquid storage tank and a liquid connection port of the expansion tank, and the first switch valve is arranged on the liquid discharge pipeline; the first temperature detection device is arranged in the environment where the expansion tank is positioned and is used for detecting the environmental temperature of the environment; pressure detection device arranged at gas connection port of expansion tankFor detecting a first pressure P of the gas in the expansion tank under the state to be detected ₁ And a second pressure P of the gas in the expansion tank in the transitional state ₂ The method comprises the steps of carrying out a first treatment on the surface of the And the flow detection device is arranged on the liquid discharge pipeline and is used for detecting the volume of liquid flowing out of the expansion tank, and the second temperature detection device is used for detecting the temperature of the liquid flowing out of the expansion tank under the state to be detected.

According to one aspect of the embodiment of the present invention, the device further comprises a controller for controlling the opening or closing of the first switch valve to turn on or off the drain line of the expansion tank under test, and according to the first pressure P ₁ Second pressure P ₂ First temperature T ₁ Volume of liquid discharged V _W Standard pressure P ₀ Standard volume V ₀ Standard temperature T ₀ Determining a first standard pressure P of the gas under the state to be measured _1t 。

According to an aspect of an embodiment of the invention, the controller is configured to respond to the first pressure P ₁ Second pressure P ₂ The volume of the discharged liquid Vw obtains the first gas volume V of the gas to be detected ₁ ；

According to the first gas volume V ₁ First temperature T ₁ Standard pressure P ₀ Volume of standard gas V ₀ Standard temperature T ₀ Acquiring a first standard pressure P of gas in a state to be detected _1t 。

According to one aspect of an embodiment of the invention, the controller determines the first gas volume V by ₁ ，

According to one aspect of an embodiment of the present invention, the controller determines the first standard pressure P by _1t ，

According to one aspect of the embodiment of the invention, the pressure detection device further comprises a liquid supplementing device, wherein the liquid supplementing device comprises a liquid supplementing pipeline, a liquid supplementing pump and a second switch valve, and two ends of the liquid supplementing pipeline are respectively connected with an outlet of the liquid storage tank and a liquid connecting port of the expansion tank; the liquid supplementing pump and the second switch valve are arranged on the liquid supplementing pipeline; the controller is also used for controlling the second switch valve to be opened, so that the liquid supplementing pipeline of the expansion tank is conducted, and the liquid with the volume Vw is injected into the expansion tank.

According to one aspect of the embodiment of the invention, the air supplementing device comprises a filter, an air supplementing pump, a third switch valve and an air conveying pipeline, wherein the filter is used for being connected with an air source, two ends of the air conveying pipeline are respectively connected with an air connecting port of the filter and an air connecting port of the expansion tank, and the air supplementing pump and the third switch valve are respectively arranged on the air conveying pipeline; the controller is also used for acquiring the allowable deviation delta P of the expansion tank; according to the first standard pressure P _1t First pressure P ₁ A differential pressure Pw is obtained, wherein pw= |p ₁ -P _1t I (I); determining whether the pressure difference Pw exceeds the allowable deviation ΔP, where Pw > ΔP, and P ₁ ＞P _1t Under the condition of +delta P, the third switch valve is controlled to be opened, so that a gas transmission pipeline of the expansion tank is conducted, and the gas in the expansion tank is discharged until the pressure in the expansion tank reaches Pw less than or equal to delta P; or at Pw > ΔP and P1 < P _1t And under the condition of delta P, controlling the third switch valve to be opened and the air supplementing pump to be started, so that the air transmission pipeline of the expansion tank is conducted, and supplementing air into the expansion tank until the pressure in the expansion tank reaches Pw less than or equal to delta P.

According to one aspect of the embodiment of the invention, the controller is used for obtaining the liquid temperature Tq flowing out of the expansion tank under the state to be tested; acquiring the ambient temperature Tg of the environment where the expansion tank is located under the state to be detected; and according to the calculation formula T1= (Tq+Tg)/2, obtaining the first temperature T of the gas in the expansion tank under the state to be detected ₁ 。。

According to an aspect of the embodiment of the present invention, the air supply device further includes a buffer tank connected to the air supply line, and the buffer tank is disposed between the third switching valve and the air supply pump.

According to a third aspect, an embodiment of the present invention provides a wind generating set, including a closed circulation system, and a pressure detection device for an expansion tank of the closed circulation system in any of the above embodiments, where a fourth switch valve is disposed at a liquid outlet of the expansion tank, a fifth switch valve is disposed at a gas connection port of the expansion tank, a liquid discharge pipeline and a liquid inlet pipeline of the pressure detection device are detachably connected with the fourth switch valve, and a gas transmission pipeline is detachably connected with the fifth switch valve.

According to the pressure detection method for the expansion tank of the closed circulation system, provided by the embodiment of the invention, the pressure standard value which is needed to be achieved by the gas in the state to be detected is calculated by measuring the change difference value of the gas volume of the expansion tank in the state to be detected and the transition state and the corresponding pressure and temperature of the expansion tank in the state to be detected and the transition state.

Drawings

Features, advantages, and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic view of a closed circulation system;

FIG. 2 is a schematic diagram of an expansion tank for a closed circulation system;

FIG. 3 is a flow chart of a method of pressure detection for an expansion tank of a closed circulation system according to one embodiment of the present invention;

FIG. 4 is a schematic view showing the structure of a pressure detecting device for an expansion tank of a closed circulation system in a state to be measured according to an embodiment of the present invention;

FIG. 5 is a schematic view of the pressure sensing apparatus for the expansion tank of the closed circulation system shown in FIG. 4 in a transitional state;

FIG. 6 is a flow chart of a method for determining a first standard pressure of a gas under test in a pressure detection method for an expansion tank of a closed loop system according to one embodiment of the present invention;

FIG. 7 is a flow chart of a method for determining a pressure difference of a gas under test in a pressure detection method of an expansion tank of a closed circulation system according to an embodiment of the present invention;

FIG. 8 is a flow chart of a method for detecting the pressure of an expansion tank of a closed circulation system for determining whether to replenish or deflate the expansion tank in a state to be measured according to an embodiment of the present invention;

FIG. 9 is a flow chart of a method for controlling the state of an expansion tank in a pressure detection method for an expansion tank of a closed cycle system according to an embodiment of the present invention;

FIG. 10 is a schematic diagram showing the connection of a controller in a pressure detection device for an expansion tank of a closed circulation system according to an embodiment of the present invention;

FIG. 11 is a schematic structural view of a pressure detecting device for an expansion tank of a closed circulation system according to another embodiment of the present invention;

FIG. 12 is a schematic diagram of a pressure detecting device according to an embodiment of the present invention.

Wherein:

100. the pressure detection device is used for the expansion tank of the closed circulation system; 200. an expansion tank; 300. a water pump; 400. a heat source; A. a liquid inlet; B. a liquid connection port; C. a liquid outlet;

10. a liquid storage device; 101. a liquid discharge pipeline; 102. a liquid storage tank; 103. a first switch valve; 104. a fourth switch valve;

20. a detection device; 201. a first temperature detection device; 202. a pressure detection device; 203. a flow rate detection device; 204. a second temperature detecting means;

30. a controller;

40. a fluid supplementing device; 401. a fluid supplementing pipeline; 402. a fluid supplementing pump; 403. a second switch valve;

50. an air supplementing device; 501. a filter; 502. a make-up pump; 503. a third switch valve; 504. a gas transmission pipeline; 505. a fifth switch valve; 506. a buffer tank;

In the drawings, like parts are designated with like reference numerals. The figures are not drawn to scale.

Detailed Description

Features and exemplary embodiments of various aspects of the invention are described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by showing examples of the invention. In the drawings and the following description, at least some well-known structures and techniques have not been shown in detail in order not to unnecessarily obscure the present invention; also, the dimensions of some of the structures may be exaggerated for clarity. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

The directional terms appearing in the following description are those directions shown in the drawings and do not limit the specific structure of the invention. In the description of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected. The specific meaning of the above terms in the present invention can be understood as appropriate by those of ordinary skill in the art.

The wind generating set is electromechanical integrated equipment for converting wind energy into electric energy, wherein the wind generating set comprises a pitch system, a yaw system, a main control system, a variable flow system, a water cooling system and the like. The control core of the fan is a variable flow system, and the state of the unit is adjusted according to the wind speed, wind direction and other parameters detected by the sensor, so that automatic control of power generation is realized. The core components in the variable flow system have the operation efficiency influenced by temperature, and when the temperature is too high or too low, the operation efficiency becomes low. Therefore, in the wind generating set, the circulating system is mainly used for cooling or heating the IGBT of the variable flow system, so that the normal operation efficiency of the IGBT is maintained, and faults are reduced.

Wind power plants are typically located in the field and are therefore typically cooled or heated using closed circulation systems. As shown in fig. 1, the closed circulation system generally includes an expansion tank 200, a water pump 300, a heat source (for heating or cooling a medium in the system) 400, and a heat exchanger 500 (typically connected to a variable flow system of a wind turbine for exchanging heat to the variable flow system). In a closed circulation system, the medium is generally liquid, and the expansion and contraction effects are obvious. Therefore, an expansion tank is additionally arranged in the circulation system to buffer the liquid volume and pressure variation in the closed circulation system, so that the stability of the system is maintained.

As shown in fig. 2, an expansion tank 200 in a closed circulation system is generally an airbag type or a diaphragm type expansion tank. And when leaving the factory, the producer also can provide the gas temperature, the gas volume and the pressure data of gas of corresponding standard operating mode.

In FIG. 2, expansion tank 200 is shown in a pre-pressurized state with expansion tank volume V ₀ The pre-charging pressure is P ₀ This pressure and the pre-charge body temperature T ₀ Corresponding to each other. This design pre-charge condition is typically provided by the expansion tank 200 supplier, which pre-charges the pressure without medium in the expansion tank, all with pre-charged gas.

After the closed circulation system is assembled, the system is filled with medium, and the gas pre-filled in the expansion tank 200 is compressed after the system is filled, so that a certain volume of medium is filled, for example, the medium filled into the expansion tank 200 occupies the total volume V of the expansion tank 200 ₀ About 40%, the ratio is not particularly limited, and the ratio is not the same for different system designs.

There are two conventional methods for detecting the gas pressure of the expansion tank 200 in the working state, in which the first method is to directly measure whether the pre-charge pressure value of the expansion tank 200 in the state to be tested reaches the standard, and determine whether to adjust the gas pressure of the expansion tank 200 according to the data of the direct test. The second method is to turn off the front and rear valves of the pump station, empty the medium in the expansion tank 200 and the water pump 300, and then perform the pre-filling pressure detection of the expansion tank 200.

However, the pressure detection method of the expansion tank 200 in the closed circulation system of the prior art cannot achieve the convenience of the operation of pressure detection while ensuring the accuracy of measurement.

Based on the above technical problems, the embodiments of the present application provide a new method for detecting the pressure of the expansion tank 200 of the closed circulation system. Firstly, the detection method does not need to completely empty the liquid in the expansion tank 200, so that the subsequent operation of liquid injection and exhaust to the pump station is omitted, the workload is reduced, the energy consumption is reduced, and the detection efficiency is improved. In addition, the method reduces the volume of the liquid in the expansion tank 200 in the state to be detected by a part to be converted into the transition state, and converts the gas ideal equation and the gas pressure, the temperature and the volume of the expansion tank 200 in the standard state by measuring the data of the gas pressure, the temperature, the liquid volume and the like in the expansion tank 200 in the state to be detected and in the transition state, so that the standard pressure corresponding to the gas mass of the expansion tank 200 in the state to be detected is accurately obtained, the accurate value of the precharge pressure adjustment can be obtained according to the detection value of the gas of the expansion tank 200 in the state to be detected and the standard pressure corresponding to the detection value, the test result is accurate, and the efficiency is high. Therefore, the error of pre-filling pressure adjustment is effectively avoided, the failure of the air bag or the diaphragm of the expansion tank 200 is prevented, the service life of the expansion tank 200 is effectively prolonged, the buffer effect is improved, and the normal and reliable operation of the closed circulation system is ensured.

In summary, the pressure detection method for the expansion tank 200 in the closed circulation system has the advantages of simple operation method and high test detection efficiency.

For a better understanding of the present invention, a method for pressure detection of the closed circulation expansion tank 200 according to the present invention will be described in detail with reference to fig. 3 to 11.

Referring to fig. 3 to 5, fig. 3 is a flow chart of a pressure detecting method for the closed circulation system expansion tank 200 according to an embodiment of the present invention, fig. 4 is a schematic diagram of a pressure detecting apparatus for the closed circulation system expansion tank 200 according to an embodiment of the present invention in a state to be measured, and fig. 5 is a schematic diagram of the pressure detecting apparatus for the closed circulation system expansion tank 200 in a transitional state shown in fig. 4.

As shown in fig. 3, the method for detecting the pressure of the expansion tank 200 of the closed circulation system according to the embodiment of the present application specifically includes the following steps:

s1, obtaining standard pressure P of gas of the expansion tank 200 in a standard state ₀ Standard volume V ₀ Standard temperature T ₀ ；

Wherein, the expansion tank 200 can be of an air bag type or a diaphragm type, and the standard state can be a factory state of the expansion tank 200, and the standard pressure P ₀ Standard volume V ₀ Standard temperature T ₀ May be a factory design parameter of expansion tank 200. Standard pressure P ₀ Standard volume V ₀ Standard temperature T ₀ In particular according to the different circulatory system requirements.

S2, obtaining a first pressure P of the gas in the expansion tank 200 under the state to be detected ₁ First temperature T ₁ ；

The first pressure P under the condition to be measured can be detected and obtained by the pressure detection device 202 arranged on the gas connection port of the expansion tank 200 ₁ 。

S3, controlling the liquid discharge pipeline 101 of the expansion tank 200 to be conducted under the state to be tested;

s4, acquiring the volume of liquid discharged by the expansion tank 200, and controlling the liquid discharge pipeline 101 to be closed when the volume of the liquid discharged is Vw, wherein the expansion tank 200 is changed into a transitional state;

in the above steps, the volume Vw of the discharged liquid is smaller than the volume L of the original liquid in the expansion tank 200 under test ₁ To ensure that the expansion tank 200 also stores the liquid L in the transitional state ₂ And gas V ₂ . Expansion tank 200 discharges a volume Vw of liquid, so that the volume of liquid of expansion tank 200 differs by Vw between the state under test and the transitional state. Volume of gas after liquid in expansion tank 200 is discharged, since the total volume in expansion tank 200 is constantAccordingly, when the liquid is discharged from the volume Vw, the gas volume is correspondingly expanded to increase the volume Vw. Thus, the difference between the volume of the gas in the transition state and the volume of the gas in the state to be measured is Vw.

S5, obtaining the second pressure P of the gas in the expansion tank 200 in the transitional state ₂ ；

Wherein the second pressure P ₂ Or can be detected by a pressure detecting device 202 provided at the gas connection port of the expansion tank 200.

S6, according to the first pressure P ₁ Second pressure P ₂ First temperature T ₁ Volume of liquid discharged V _W Standard pressure P ₀ Standard volume V ₀ Standard temperature T ₀ Determining a first standard pressure P of the gas under the state to be measured _1t 。

In the pressure detection method for the expansion tank 200 of the closed circulation system provided by the embodiment of the invention, the difference Vw of the gas volume of the expansion tank 200 in the state to be detected and the transition state is measured, and the corresponding first pressure P in the state to be detected and the transition state is measured ₁ Second pressure P ₂ First temperature T ₁ In combination with standard pressure P in standard state ₀ Standard volume V ₀ Standard temperature T ₀ Calculating standard pressure P to be reached by gas under the state to be detected _1t 。

According to the detection method, liquid in the expansion tank 200 is not required to be completely emptied, so that subsequent operation of liquid injection and exhaust to a pump station is omitted, the workload is reduced, the energy consumption is reduced, and the detection efficiency is improved. In addition, the detection method of the present application reduces Vw the volume of the liquid in the expansion tank 200 under the state to be detected to switch to the transition state by measuring the first pressure P in the expansion tank under the state to be detected and the transition state ₁ Second pressure P ₂ First temperature T ₁ In combination with standard pressure P in standard state ₀ Standard volume V ₀ Standard temperature T ₀ And the ideal gas equation is converted to obtain the standard pressure P corresponding to the gas mass of the expansion tank 200 under the state to be measured more accurately _1t Thereby being capable of detecting the value P of the gas of the expansion tank 200 in the state to be detected ₁ And standard pressure P that should correspond to _1t Whether the pre-charging pressure is adjusted or not and the accurate value of the pre-charging pressure adjustment are determined more accurately, the test result is accurate, and the efficiency is high. Therefore, the error of pre-filling pressure adjustment is effectively avoided, the failure of the air bag or the diaphragm of the expansion tank 200 is prevented, the service life of the expansion tank 200 is effectively prolonged, the buffer effect is improved, and the normal and reliable operation of the closed circulation system is ensured. In summary, the pressure detection method for the expansion tank 200 in the closed circulation system has the advantages of simple operation method and high test detection efficiency.

As an alternative embodiment, the gas volume difference Vq between the state under test and the transition state in the expansion tank 200 is equal to the discharged liquid volume Vw. As shown in fig. 4 and 5, fig. 4 shows a schematic diagram of the liquid and the gas in the expansion tank 200 in the state to be measured, and fig. 5 shows a schematic diagram of the liquid and the gas in the expansion tank 200 in the transition state. It will be appreciated that the illustration in the above figures is merely an example and does not represent the exact volumes of liquid and gas in expansion tank 200.

As shown in fig. 4 and 5, the volume of the liquid in the state to be measured is L ₁ The volume of the liquid in the transition state is L ₂ 。

In the present embodiment, assuming that the total volume of the expansion tank 200 is V, where the volume of gas is Vg and the volume of liquid is Vq, v=vg+vq. When the volume of the discharged liquid is Vw, the volume of the liquid in the expansion tank 200 is reduced by Vw, and the sum of the volumes of the gas and the liquid is constant, so that the volume of the gas is relatively increased by Vw. Let the first gas volume be V ₁ A second volume of V ₂ Thus, it is possible to obtain,

L ₁ -L ₂ ＝V ₂ -V ₁ ＝Vw (1)。

in the above technical solution, the volume change of the gas in the expansion tank 200 can be obtained by measuring the volume change of the liquid in the expansion tank 200, and the measurement method is simple and convenient, and the result is accurate.

Referring to fig. 6 in combination, step S6 includes:

s61, according to the first pressure P ₁ Second pressure P ₂ The volume of the discharged liquid Vw obtains the first gas volume V of the gas to be detected ₁ ；

Wherein the first gas volume V ₁ That is, the volume of the gas in the expansion tank 200 in the state to be measured is determined first, and the volume V is calculated ₁ First standard pressure P as a standard mass of gas in a first gas volume state _1t Is a calculation basis of (a).

S62, according to the first gas volume V ₁ First temperature T ₁ Standard pressure P ₀ Volume of standard gas V ₀ Standard temperature T ₀ Acquiring a first standard pressure P of gas in the expansion tank 200 to be tested _1t . In other words, the first standard pressure P _1t Is the standard pressure corresponding to the gas mass in the standard state in the state to be measured.

As an alternative embodiment, in step S61, the first gas volume V is determined by the following formula ₁ ,

The above equation is obtained by conversion according to the ideal gas equation, specifically, the gas mass in the expansion tank 200 is unchanged in the state to be measured and the transition state according to

PV＝nRT (2)。

It can be known that the ideal equation of the gas to be measured is,

P ₁ V ₁ ＝nRT ₁ (3)；

the ideal equation for the transition state gas is that,

P ₂ V ₂ ＝nRT ₂ (4)；

as the detection process is carried out when the circulating system is static in the operation and maintenance state, the liquid cooling medium and the gas are not heated or cooled for a short timeThe temperature of the medium in the space and the ambient temperature change little, so in the present application, in order to simplify the calculation process while improving the detection accuracy, the first temperature T in the expansion tank 200 is set ₁ And a second temperature T ₂ Are identical. Thus T is ₁ ＝T ₂ Thereby obtaining

P ₁ V ₁ ＝P ₂ V ₂ (5)；

Conversion can be obtained

As an alternative embodiment, in step S62, the first standard pressure P is determined by the following formula _1t ,

Specifically, the first standard pressure P _1t The calculation formula is obtained by converting an ideal gas equation:

in a first step, by bringing formula (6) into formula (1)

The second step, the equation is converted to obtain,

the first gas volume V of the gas portion in the expansion tank 200 can be calculated in the state to be measured ₁ 。

Third, if necessary, calculate the first standard pressure P of the gas portion in the expansion tank 200 under test _1t Assuming that the expansion tank 200 has the same mass of gas as in the standard condition, the first standard pressure under test isP _1t From Boyle's law

Fourth, the formula (9) is converted to obtain,

by the method, the corresponding first pressure P of the expansion tank 200 in the state to be measured, the transition state and the standard state is obtained ₁ Second pressure P ₂ First gas volume V ₁ And the pressure difference Vw is converted by combining an ideal gas equation, and the accurate first gas volume V of the gas part under the state to be detected is calculated first ₁ In combination with the standard pressure P of the standard state of the expansion tank 200 ₀ Standard volume V ₀ Standard temperature T ₀ Calculating a first standard pressure P to be reached in a state to be measured _1t The calculation result is accurate and reliable, and the operation is convenient and the efficiency is high.

As an alternative implementation manner, the pressure detection method for the expansion tank 200 of the closed circulation system according to the embodiment of the present invention further includes step S7, and is shown with reference to fig. 5 and 7, where fig. 5 is a schematic structural diagram of the pressure detection device for the expansion tank of the closed circulation system in the transitional state shown in fig. 4, and fig. 7 is a flow chart diagram for determining the pressure difference of the gas in the state to be detected in the pressure detection method for the expansion tank of the closed circulation system according to the embodiment of the present invention. As shown in fig. 7, step S7 includes:

s71, controlling a liquid supplementing pipeline 401 of the expansion tank 200 to be communicated, and injecting liquid with the volume Vw into the expansion tank 200;

s72, according to the first standard pressure P _1t First pressure P ₁ A differential pressure Pw is obtained, wherein pw= |p ₁ -P _1t I (I); the expansion tank 200 is replenished with gas or exhausted with gas according to the pressure difference Pw.

The above stepsIn the step of replenishing Vw liquid into the expansion tank 200, the expansion tank 200 is adjusted from a transition state to a state to be measured, and the volume of the gas in the expansion tank 200 is the first gas volume V ₁ The gas pressure is the first pressure P ₁ By applying the actual first gas pressure P in the state to be measured ₁ With a first standard pressure P _1t Comparing to obtain a first pressure P ₁ With a first standard pressure P _1t Is a difference in (c). When the difference is large, the amount of gas in the expansion tank 200 needs to be adjusted.

In the above embodiment, the liquid of volume Vw discharged in step S2 is refilled into the expansion tank 200 and is according to the first pressure P ₁ With a first standard pressure P _1t The difference value of (2) adjusts the gas amount in the expansion tank 200, so that whether the precharge pressure should be adjusted or not can be accurately determined, an accurate value of precharge pressure adjustment is obtained, a test result is accurate, and efficiency is high.

Further, the method for detecting the pressure of the expansion tank 200 of the closed circulation system according to the embodiment of the invention further includes step S8, refer to fig. 5 and fig. 8, wherein fig. 8 is a flow chart of the method for detecting the pressure of the expansion tank of the closed circulation system according to the embodiment of the invention, wherein the flow chart is used for determining whether to-be-detected air is supplied or discharged to the expansion tank. As shown in fig. 8, step S72 includes:

s72a, acquiring an allowable deviation delta P of the gas pressure of the expansion tank 200;

s72b, according to the first standard pressure P _1t First pressure P ₁ A differential pressure Pw is obtained, wherein pw= |p ₁ -P _1t |

S72c, determining whether the pressure difference Pw exceeds the allowable deviation ΔP, where Pw > ΔP, and P ₁ ＞P _1t In the case of +Δp, the gas line 504 of the expansion tank 200 is controlled to be connected to discharge the gas in the expansion tank 200 until the pressure in the expansion tank 200 reaches Pw less than or equal to Δp; or at Pw > ΔP, and P ₁ ＜P _1t In the case of ΔP, gas line 504 of expansion tank 200 is controlled to conduct, replenishing gas into expansion tank 200 until the pressure in expansion tank 200 reaches Pw.ltoreq.ΔP.

In the above technical solution, considering the allowable deviation Δp of the gas pressure in the expansion tank 200 under the actual state to be measured, when the pressure difference Pw is greater than the allowable deviation Δp, the amount of gas in the expansion tank 200 needs to be adjusted. Specifically, when P ₁ ＞P _1t In +Δp, it means that a part of the gas is sucked into the expansion tank 200 during operation and the amount of the sucked gas is larger than the allowable deviation Δp, so that it is necessary to release a part of the gas in the expansion tank 200 to bring the pressure difference Pw within the allowable deviation Δp. When P ₁ ＜P _1t In +Δp, it means that a part of the gas leaks into the expansion tank 200 during operation and the amount of the leaked gas is smaller than the allowable deviation Δp, so that it is necessary to supplement a part of the gas into the expansion tank 200 to bring the differential pressure Pw within the allowable deviation Δp.

The operation mode is simple and convenient, the calculation result is accurate, the gas quantity in the expansion tank 200 can be kept in a standard state, and the stable operation of the closed circulation system can be ensured.

As an alternative embodiment, referring to fig. 9, a first pressure P of the gas in the expansion tank 200 under test is obtained ₁ Before the step, the method further comprises the following steps:

s1.5, controlling the liquid supplementing pipeline 401, the liquid discharging pipeline 101 and the gas conveying pipeline 504 of the expansion tank 200 in a state to be tested to be closed. The gas and liquid in the expansion tank 200 can not flow under the state to be detected, and the first pressure P detected under the state to be detected can be effectively ensured ₁ Accuracy of (3).

As an alternative embodiment, a first temperature T of the gas in the expansion tank 200 under test is obtained ₁ Comprising: acquiring the liquid temperature Tq flowing out of the expansion tank 200 in a state to be detected; acquiring the ambient temperature Tg of the environment where the expansion tank 200 is located under the state to be detected; according to the calculation formula T ₁ = (tq+tg)/2, and the first temperature T of the gas in the expansion tank 200 in the state to be measured is obtained ₁ . First temperature T under test ₁ The first temperature T of the gas in expansion tank 200 is calculated from the ambient temperature Tg and the temperature Tq of the liquid in expansion tank 200 ₁ Is used for accurately acquiring the gas in the expansion tank 200 under the condition that the temperature detection device cannot be arranged in the expansion tank 200First temperature T of body ₁ Is a method of (2).

In another aspect, an embodiment of the present invention provides a pressure detecting apparatus 100 for an expansion tank 200 of a closed circulation system for implementing the pressure detecting method in the above embodiment. With continued reference to fig. 4 and 5, the pressure detecting device 100 for the expansion tank 200 of the closed circulation system includes a liquid storage device 10 and a detecting device 20. The detection device 20 includes a first temperature detection device 201, a pressure detection device 202, a flow detection device 203, and a second temperature detection device 204.

Specifically, the liquid storage device 10 includes a liquid discharge pipe 101, a liquid storage tank 102, and a first switch valve 103. Wherein, two ends of the liquid discharge pipeline 101 are respectively connected with a liquid inlet of the liquid storage tank 102 and a liquid connection port of the expansion tank 200, and the first switch valve 103 is arranged on the liquid discharge pipeline 101; the first temperature detecting device 201 is disposed in the environment where the expansion tank 200 is located, and is used for detecting the ambient temperature of the environment. The pressure detecting device 202 is disposed at the gas connection port of the expansion tank 200, and is used for detecting a first pressure P of the gas in the expansion tank 200 under the condition to be detected ₁ And a second pressure P of the gas in the expansion tank 200 in the transitional state ₂ . The flow rate detection device 203 and the second temperature detection device 204 are respectively provided on the drain line 101. The flow detection device 203 is used for detecting the volume of the liquid flowing out of the expansion tank 200, and the second temperature detection device 204 is used for detecting the temperature of the liquid flowing out of the expansion tank 200 under the state to be detected.

In the above technical solution, the liquid storage tank 102 is provided to store the liquid discharged from the expansion tank 200, so as to facilitate the change of the expansion tank 200 from the state to be measured to the transition state, and the detection device 20 is provided to accurately measure the data of the liquid and the gas in the expansion tank 200, and the measurement data obtained by the detection method is used to determine the first standard pressure P of the gas in the state to be measured _1t In turn, determines a first pressure P of the gas within expansion tank 200 ₁ With a first standard pressure P _1t The accurate difference value between the two components avoids the attenuation or failure of the buffer effect caused by the rupture of a diaphragm or an air bag in the expansion tank 200 due to the error calculation of the difference value, and ensures the stable and reliable operation of the system. Also, there is no need to use the liquid in expansion tank 200And the device is completely emptied, so that a special medium collecting container is not required, the subsequent operations of supplementing and exhausting the liquid in the expansion tank 200 are omitted, the operation difficulty is greatly reduced, the workload of manual operation is reduced, and the detection efficiency and accuracy are improved.

As an alternative embodiment, the pressure detecting device 100 for the expansion tank 200 of the closed circulation system further includes a controller 30, and as shown in fig. 10, the controller 30 is electrically connected to the first switching valve 103, the flow rate detecting device 203, the first temperature detecting device 201, the second temperature detecting device 204, and the pressure detecting device 202, respectively.

The controller 30 can control the opening or closing of the first switch valve 103 to switch on or off the liquid discharge pipeline 101 of the expansion tank 200 under the state to be tested. Meanwhile, the controller 30 may also respond to the first pressure P ₁ Second pressure P ₂ First temperature T ₁ Volume of liquid discharged V _W Standard pressure P ₀ Standard volume V ₀ Standard temperature T ₀ Determining a first standard pressure P of the gas under the state to be measured _1t 。

By arranging the controller 30, various data of the expansion tank 200 in a state to be detected and a transition state can be automatically acquired, and the opening or closing of the first switch valve 103 is automatically controlled, so that the workload of manual labor is reduced, the efficiency is improved, and the detection accuracy is improved.

As an alternative embodiment, the controller 30 is configured to respond to the first pressure P ₁ Second pressure P ₂ The volume of the discharged liquid Vw obtains the first gas volume V of the gas to be detected ₁ . And, moreover, the method comprises the steps of. The controller 30 may be responsive to the first gas volume V ₁ First temperature T ₁ Standard pressure P ₀ Volume of standard gas V ₀ Standard temperature T ₀ Acquiring a first standard pressure P of gas in a state to be detected _1t 。

As an alternative embodiment, the controller 30 may determine the first gas volume V by ₁ ，

The above technical solution uses the controller 30 to control the first gas volume V ₁ And the calculation is performed, so that the calculation efficiency is improved.

As an alternative embodiment, controller 30 may also determine first standard pressure P by _1t ，

As an alternative embodiment, the pressure detecting device 100 for the expansion tank 200 of the closed circulation system further includes a fluid supplementing device 40, and the fluid supplementing device 40 includes a fluid supplementing pipe 401, a fluid supplementing pump 402, and a second switch valve 403. Specifically, two ends of the fluid-filling pipeline 401 are respectively connected with the outlet of the fluid storage tank 102 and the fluid connection port of the expansion tank 200. A fluid replacement pump 402 and a second on-off valve 403 are provided in the fluid replacement line 401. The controller 30 is electrically connected to the fluid infusion pump 402 and the second switch valve 403, respectively, to control the second switch valve 403 to be opened, so as to conduct the fluid infusion line 401 of the expansion tank 200, and to inject the fluid with volume Vw into the expansion tank 200.

In the fluid replacement device 40 having the above-described structure, the fluid replacement line 401 is provided to directly connect the reservoir tank 102 and the expansion tank 200. The second switch valve 403 is used for controlling the on-off of the fluid infusion line 401, so as to control the fluid infusion operation, and improve the accuracy of the fluid infusion operation. And, the setting controller 30 is electrically connected with the fluid infusion pump 402 and the second switch valve 403, respectively, for automatically controlling and switching the expansion tank 200 from the transitional state to the state to be tested, thereby improving the convenience of operation.

By providing the liquid replenishing means 40, the discharged liquid is returned to the expansion tank 200. Therefore, the liquid supplementing device 40 can supplement the liquid in the expansion tank 200, and keep the gas volume in the expansion tank 200 to be the first gas volume V ₁ The volume of the medium in the closed circulation system is kept unchanged, and the normal operation of the system is ensured. Thus, when expanding the medium within tank 200After the replenishment, the volume of the gas and the volume of the medium in the expansion tank 200 are restored to the state to be measured. The subsequent air supplementing operation is carried out under the state to be tested, so that the accuracy of the volume of the supplemented or discharged air is ensured. The structure can realize fluid infusion under a complete closed state, ensures stable operation of the system, and is simple and efficient to operate.

As an alternative implementation, the pressure detecting device 100 for the expansion tank 200 of the closed circulation system according to the embodiment of the present application further includes a gas supplementing device 50, where the gas supplementing device 50 includes a filter 501, a gas supplementing pump 502, a third switch valve 503, and a gas transmission pipeline 504.

Specifically, the filter 501 is used to connect to a gas source, which may be air or nitrogen. The filter 501 is used to filter impurities in the gas and prevent the impurities in the gas from damaging the expansion tank 200. The two ends of the gas transmission pipeline 504 are respectively connected with the gas connectors of the filter 501 and the expansion tank 200, and are used for performing gas supplementing or deflating operation on the expansion tank 200. The air supplementing pump 502 and the third switch valve 503 are respectively disposed on the air transmission pipeline 504, and the air supplementing pump 502 is used for supplementing air in the expansion tank 200, so as to improve air supplementing efficiency. The third switch valve 503 is used to control the opening or closing of the gas line 504.

Because the liquid in the liquid storage tank 102 returns to the expansion tank 200 again and can perform the air supplementing or deflating operation on the expansion tank 200, the pressure detection device 100 provided by the application can repeatedly use for detecting the pre-filling pressure of the expansion tank 200. Especially when the device is applied to the wind turbine generator system, the device can be integrally arranged on the wind turbine generator system for online control and periodically and automatically run.

The controller 30 is further electrically connected to the air supplementing pump 502 and the third switch valve 503, respectively, for obtaining the allowable deviation Δp of the expansion tank 200; according to standard pressure P _1t First pressure P ₁ The differential pressure Pw is obtained. Wherein pw= |p ₁ -P _1t I (I); determining whether the pressure difference Pw exceeds the allowable deviation ΔP, where Pw > ΔP, and P ₁ ＞P _1t In the case of +Δp, the third switching valve is controlled to be opened to conduct the gas supply line 504 of the expansion tank 200, thereby discharging the gas in the expansion tank 200 until expansionThe pressure in the expansion tank 200 reaches Pw.ltoreq.ΔP; or at Pw > ΔP, and P ₁ ＜P _1t In case of Δp, the third switch valve 503 is controlled to be opened and the make-up pump 502 is controlled to be started, so that the gas transmission pipeline 504 of the expansion tank 200 is conducted, and the gas is supplemented into the expansion tank 200 until the pressure in the expansion tank 200 reaches Pw less than or equal to Δp.

By arranging the controller 30, the gas control of the expansion tank 200 can be controlled fully automatically for 24 hours according to the automatic control of the gas supplementing and discharging operation of the expansion tank 200, the manual labor is greatly reduced, the operation efficiency is improved, and the gas control of the expansion tank 200 is controlled fully automatically according to the first pressure P ₁ With a first standard pressure P _1t The difference value of the pressure sensor is used for adjusting the gas quantity in the expansion tank, so that whether the pre-charging pressure is adjusted or not and the accurate value of the pre-charging pressure adjustment can be accurately determined, the long-term stable operation of the wind turbine generator set is ensured, and the service life of the wind turbine set is prolonged.

As an alternative embodiment, as shown in fig. 11, the air supplementing device 50 further includes a buffer tank 506 connected to the air pipeline 504, where the buffer tank 506 is disposed between the third switch valve 503 and the air supplementing pump 502, and the buffer tank 506 is used to buffer the fluctuation of the air supplementing pressure, so as to ensure the stability of the air pressure in the air pipeline 504 and the expansion tank 200 during air supplementing.

As an alternative embodiment, the controller 30 is configured to obtain the temperature Tq of the liquid flowing out of the expansion tank 200 under test; acquiring the ambient temperature Tg of the environment where the expansion tank 200 is located under the state to be detected; and according to the calculation formula T ₁ = (tq+tg)/2, and the first temperature T of the gas in the expansion tank 200 in the state to be measured is obtained ₁ . The liquid temperature Tq of the expansion tank 200 and the ambient temperature Tg are obtained by the controller 30, and the first temperature T is automatically calculated ₁ 。

The above technical solution has two effects, on the one hand, the controller 30 can timely obtain the gas temperature change of the expansion tank 200 of the closed circulation system, and ensure the stable operation of the system. Second, the controller 30 can also obtain the temperature of the gas under test and provide data for subsequent calculation of the first standard pressure.

In another aspect, an embodiment of the present invention further provides a wind generating set, including a closed circulation system, and the pressure detection device 100 for an expansion tank 200 of the closed circulation system in any of the foregoing embodiments, where a fourth switch valve 104 is disposed at a liquid outlet of the expansion tank 200, a fifth switch valve 505 is disposed at a gas connection port of the expansion tank 200, and a liquid discharge pipeline 101 and a liquid inlet pipeline of the pressure detection device 100 for the expansion tank 200 of the closed circulation system are detachably connected to the fourth switch valve 104, and a gas transmission pipeline 504 is detachably connected to the fifth switch valve 505. The pressure detecting device 100 for the closed circulation system expansion tank 200 can be flexibly connected to the wind power generation set in a detachable manner. Similarly, the detection device can be fixedly connected with the wind generating set to control the wind generating set in real time. The specific connection manner may be set as required, and will not be described here.

With continued reference to fig. 4, 5 and 12, the following describes a specific operation of the present application for pressure sensing of an expansion tank 200 in a cooling circulation system (as shown in fig. 1) of a wind turbine generator set using an embodiment of the pressure sensing apparatus 100 provided herein for an expansion tank 200 of a closed circulation system.

As shown in fig. 1, the closed circulation system includes an expansion tank 200, a water pump 300, a heat source 400, a heat exchanger 500, and other necessary valves, sensors, and the like. The invention is applicable to all closed circulation systems of wind power, and the expansion tank 200 configured by the closed circulation system can be of an air bag type or a diaphragm type. The heat exchanger 500 is typically connected to a variable flow system of the electrode assembly for exchanging heat to the variable flow system. The heat source 400 may heat or cool the medium in the system.

As shown in fig. 3, 4 and 12, the pressure detection device 100 for the closed circulation system expansion tank 200 includes a liquid storage device 10, a detection device 20, a controller 30, a liquid replenishing device 40 and a gas replenishing device 50.

The liquid storage device 10 is used for storing liquid in the expansion tank 200, the detection device 20 is used for acquiring various state data of the expansion tank 200, the liquid supplementing device 40 is used for supplementing or recovering the liquid in the expansion tank 200, and the air supplementing device 50 is used for supplementing or recovering air in the expansion tank 200. The controller 30 is electrically connected with the liquid storage device 10, the detection device 20, the liquid supplementing device 40 and the air supplementing device 50 respectively, and controls the automatic operation of the devices.

In the embodiment of the present application, the liquid storage device 10 includes a liquid discharge pipe 101, a liquid storage tank 102, and a first switch valve 103. Wherein, two ends of the liquid discharge pipeline 101 are respectively connected with a liquid inlet a of the liquid storage tank 102 and a liquid connection port B of the expansion tank 200 (a fourth switch valve 104 is disposed at the position of the liquid connection port B generally), the first switch valve 103 is disposed on the liquid discharge pipeline 101, specifically, an inlet and an outlet of the first switch valve 103 are respectively connected to an outlet of the flow detection device 203 and a liquid inlet of the liquid storage tank 102. The liquid storage tank 102 is provided with a liquid inlet A and a liquid outlet C. Of course, in other embodiments, the liquid inlet and the liquid outlet of the liquid storage tank 102 may be a liquid connection port, and the above structure can achieve the technical effects of the present embodiment, which is not limited herein.

The detection device 20 includes a first temperature detection device 201, a pressure detection device 202, a flow detection device 203, and a second temperature detection device 204. The first temperature detecting device 201 is disposed in the environment of the expansion tank 200, and is used for detecting the ambient temperature of the surrounding environment. The pressure detecting device 202 is disposed at the gas connection port of the expansion tank 200 (typically, a third switch valve 505 is disposed at the gas connection port, as shown in fig. 1, the pressure detecting device 202 is connected between the third switch valve 503 and the fifth switch valve 505 of the gas connection port of the expansion tank 200) for detecting the first pressure P of the gas in the expansion tank 200 under test ₁ And a second pressure P of the gas in the expansion tank 200 in the transitional state ₂ . The flow rate detection device 203 and the second temperature detection device 204 are respectively provided in the drain line 101. The flow detection device 203 is used for detecting the volume of the liquid flowing out of the expansion tank 200, and the second temperature detection device 204 is used for detecting the temperature of the liquid flowing out of the expansion tank 200 under the state to be detected.

The fluid infusion device 40 includes a fluid infusion line 401, a fluid infusion pump 402, and a second switch valve 403. Specifically, two ends of the fluid-filling pipeline 401 are respectively connected with the outlet of the fluid storage tank 102 and the fluid connection port of the expansion tank 200. A fluid replacement pump 402 and a second on-off valve 403 are provided in the fluid replacement line 401.

The air supplementing device 50 comprises a filter 501, an air supplementing pump 502, a third switch valve 503 and an air conveying pipeline 504. The filter 501 is used in conjunction with a gas source, which may be air or nitrogen. The filter 501 is used to filter impurities in the gas to prevent damage to the expansion tank 200 caused by the impurities in the gas. The two ends of the gas transmission pipeline 504 are respectively connected with the gas connectors of the filter 501 and the expansion tank 200, and are used for performing gas supplementing or deflating operation on the expansion tank 200. The air supplementing pump 502 and the third switch valve 503 are respectively disposed on the air transmission pipeline 504, and the air supplementing pump 502 is used for supplementing air to the expansion tank 200. The third switch valve 503 is used to control the opening or closing of the gas line 504.

Specifically, the controller 30 is electrically connected to the first switch valve 103, the flow rate detecting device 203, the first temperature detecting device 201, the second temperature detecting device 204, the pressure detecting device 202, the fluid supplementing pump 402, the second switch valve 403, the fluid supplementing pump 502, and the third switch valve 503, respectively,

the controller 30 is configured to control the first switch valve 103 to be opened or closed, to turn on or off the liquid discharge pipeline 101 of the expansion tank 200 under the condition to be tested, and to control the second switch valve 403 to be opened, to turn on the liquid supplementing pipeline 401 of the expansion tank 200, and to inject the liquid with volume Vw into the expansion tank 200. The controller 30 is also electrically connected to the expansion tank 200 for obtaining an allowable deviation ΔP and for obtaining a first pressure P ₁ Second pressure P ₂ First temperature T ₁ Volume of liquid discharged V _W Standard pressure P ₀ Standard volume V ₀ Standard temperature T ₀ Determining a first standard pressure P of the gas under the state to be measured _1t 。

In the embodiment of the present application, the controller 30 is further provided with a calculation module, and after the controller 30 obtains the above data, the calculation module may be according to the following

Calculating the first gas volume V1 and then passing

Determining a first standard pressure P _1t 。

When the pressure detection device 100 for the expansion tank 200 of the closed circulation system is used for detecting the pressure in the expansion tank 200, the method specifically comprises the following steps:

s1, the controller 30 obtains the standard pressure P of the gas of the expansion tank 200 in the standard state ₀ Standard volume V ₀ Standard temperature T ₀ . The parameter may be input, for example, by way of an input, to be stored in the controller. The expansion tank 200 may be of a balloon type or a diaphragm type, and the standard state may be a factory state of the expansion tank 200.

S00, opening a fourth switch valve 104 at the liquid connection port of the expansion tank and a valve at the gas connection port.

S0, the controller 30 controls the first switch valve 103, the second switch valve 403 and the third switch valve 503 to be closed, namely controls the liquid supplementing pipeline 401, the liquid discharging pipeline 101 and the gas conveying pipeline 504 of the expansion tank 200 to be closed under the state to be tested. The gas and the liquid in the expansion tank 200 can not flow under the state to be detected, so that the accuracy of the detection data under the state to be detected is ensured;

S2, the controller 30 obtains the first pressure P of the gas in the expansion tank 200 under the state to be measured ₁ And calculate the first temperature T ₁ The method comprises the steps of carrying out a first treatment on the surface of the The steps may include:

s21, acquiring a first pressure P under a state to be detected by a pressure detection device 202 arranged on a gas connection port of the expansion tank 200 ₁ ；

S22, acquiring the liquid temperature Tq flowing out of the expansion tank 200 in a state to be detected through the second temperature detection device 204; the first temperature detection device 201 obtains the ambient temperature Tg of the environment in which the expansion tank 200 is located in a state to be measured; according to the calculation formula T ₁ = (tq+tg)/2, and the first temperature T of the gas in the expansion tank 200 in the state to be measured is obtained ₁ . In the state to be measuredThe temperature of the gas in the expansion tank 200 is calculated from the ambient air temperature and the liquid temperature in the expansion tank 200, and when the temperature detection device cannot be provided in the expansion tank 200, the temperature of the gas in the expansion tank 200 can be accurately obtained.

It will be appreciated that the order of steps S21 and S22 described above may be interchanged, and is not limited thereto.

S3, the controller 30 controls the first switch valve 103 to be opened, namely controls the liquid discharge pipeline 101 of the expansion tank 200 to be conducted under the state to be tested.

And S4, the controller 30 acquires the volume of the liquid discharged by the expansion tank 200 (detected by the flow detection device 203), and when the volume of the liquid discharged is Vw, the controller 30 controls the first switch valve 103 to be closed, namely controls the liquid discharge pipeline 101 to be closed, and the expansion tank 200 is in a transitional state. By controlling the conduction and closing of the drain line 101 of the expansion tank 200, the state of the expansion tank 200 is switched from the state to be measured to the transitional state, and the operation is convenient.

The volume Vw of the discharged liquid is smaller than the volume of the original liquid in the expansion tank 200 under the state to be measured, and the liquid and the gas are also stored in the expansion tank 200 under the transition state, and the volume of the liquid under the transition state is different by Vw, so that the mass of the gas is equal to the mass of the gas under the state to be measured.

S5, acquiring a second pressure P of the gas in the expansion tank 200 in the transitional state through the pressure detection device 202 ₂ ；

S6, according to the first pressure P ₁ Second pressure P ₂ First temperature T ₁ The volume Vw of the liquid discharged, the standard pressure P ₀ Standard volume V ₀ Standard temperature T ₀ Determining a first standard pressure P of the gas under the state to be measured _1t . The steps may include:

s61, according to the first pressure P ₁ Second pressure P ₂ The volume of the discharged liquid Vw obtains the first gas volume V of the gas to be detected ₁ The method comprises the steps of carrying out a first treatment on the surface of the First gas volume V ₁ I.e. the volume of gas in the expansion tank 200 in the state to be measured. Firstly, determining the volume of gas under the state to be measured as a standard under the state of the volume of the first gasThe pressure of the gas of the mass is calculated as a basis. The present embodiment can determine the first gas volume V by ₁ ,

The calculation process described above may obtain the first pressure P at the controller 30 ₁ Second pressure P ₂ And the discharged liquid volume Vw data, is automatically calculated by the controller 30.

S62, according to the first gas volume V ₁ First temperature T ₁ Standard pressure P ₀ Volume of standard gas V ₀ Standard temperature T ₀ Acquiring a first standard pressure P of gas in a state to be detected _1t . First standard pressure P _1t The corresponding gas mass is the standard state, and the corresponding standard pressure is the standard pressure in the state to be measured. The present embodiment can determine the first standard pressure P by the following formula _1t ,

The controller 30 obtains a first gas volume V ₁ First temperature T ₁ Standard pressure P ₀ Volume of standard gas V ₀ Standard temperature T ₀ Thereafter, the first standard pressure P may be obtained by automatic calculation by the controller 30 _1t 。

S7, calculating the gas pressure difference Pw can comprise:

and S71, the controller 30 controls the second switch valve 403 to be opened, namely controls the liquid supplementing pipeline 401 of the expansion tank 200 to be conducted, re-injects the liquid with the volume Vw into the expansion tank 200 from the liquid storage tank 102, controls the second switch valve 403 to be closed after the filling is finished, and controls the liquid supplementing pump 402 to stop running, so that the gas state in the expansion tank of the liquid cooling system is restored to the state to be detected. Because air does not enter the liquid cooling system in the liquid discharging process, the liquid cooling system does not need to be exhausted after the liquid supplementing is completed;

S72, according to standard pressure P _1t First pressure P ₁ A differential pressure Pw is obtained, wherein pw= |p ₁ -P _1t I (I); the expansion tank 200 is replenished with gas or exhausted with gas according to the pressure difference Pw.

Wherein S72, the operation of supplementing or deflating the expansion tank 200 can comprise

s72b, according to the first standard pressure P _1t First pressure P ₁ A differential pressure Pw is obtained, wherein pw= |p ₁ -P _1t |；

S72c, determining whether the pressure difference Pw exceeds the allowable deviation ΔP, where Pw > ΔP, and P ₁ ＞P _1t In the case of +Δp, the controller 30 controls the third switch valve 503 to open, i.e. controls the gas transmission pipeline 504 of the expansion tank 200 to be turned on, so as to exhaust the gas in the expansion tank 200 and reduce P ₁ Until the pressure in expansion tank 200 reaches Pw.ltoreq.ΔP; or at Pw > ΔP, and P ₁ ＜P _1t In case of Δp, the controller 30 controls the third switch valve 503 to open, i.e. controls the gas transmission pipeline 504 of the expansion tank 200 to be turned on, and controls the gas supplementing pump 502 to start, supplementing gas into the expansion tank 200, and increasing P ₁ Until the pressure in expansion tank 200 reaches Pw +.Δp.

In some embodiments, the above calculation process may also be performed automatically by the controller 30, so as to improve the calculation efficiency. For example, the controller 30 may continuously acquire the above data for 24 hours, and calculate the data, and control the automatic air supply and air discharge operation of the expansion tank 200 according to the calculation result. The implementation of the method can be automatically controlled by the controller 30, so that the stable operation of the closed circulation system can be effectively ensured, and the service life of the closed circulation system can be prolonged.

It should be noted that, the electrical connection referred to in the present application may be understood as a line electrical connection, or may be understood as a communication connection, or the like, as long as the connection that enables signal transmission between the controller and each device is achieved.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims

1. The pressure detection method for the expansion tank of the closed circulation system is characterized in that liquid and gas are stored in the expansion tank under the state to be detected, and the pressure detection method comprises the following steps:

obtaining the standard pressure P of the expansion tank gas under the standard state ₀ Standard volume V ₀ Standard temperature T ₀ ；

Acquiring a first pressure P of gas in the expansion tank under the state to be detected ₁ First temperature T ₁ ；

Controlling the conduction of a liquid discharge pipeline of the expansion tank under the state to be detected;

Acquiring the volume of liquid discharged by the expansion tank, and controlling the liquid discharge pipeline to be closed when the volume of the liquid discharged is Vw, wherein the expansion tank is in a transitional state;

acquiring a second pressure P of the gas in the expansion tank in the transition state ₂ ；

According to the first pressure P ₁ Said second pressure P ₂ Said first temperature T ₁ Volume of liquid discharged V _W The standard pressure P ₀ Said standard volume V ₀ Said standard temperature T ₀ Determining a first standard pressure P of the gas under the state to be detected _1t 。

2. The pressure detection method for an expansion tank of a closed circulation system according to claim 1, wherein a gas volume difference Vq of the state to be detected and the transition state in the expansion tank is equal to the discharged liquid volume Vw.

3. The pressure detection method for an expansion tank of a closed circulation system according to claim 1, characterized in that according to the first pressure P ₁ Said second pressure P ₂ Said first temperature T ₁ Volume of liquid discharged V _W The standard pressure P ₀ Said standard volume V ₀ Said standard temperature T ₀ Acquiring a first standard pressure P of the gas in the expansion tank under the state to be detected _1t Comprising:

according to the first pressure P ₁ Second pressure P ₂ The volume V of the discharged liquid _W Acquiring a first gas volume V of the gas to be detected ₁ ；

According to the first gas volume V ₁ First temperature T ₁ Standard pressure P ₀ Volume of standard gas V ₀ Standard temperature T ₀ Acquiring a first standard pressure P of the gas in the state to be detected _1t 。

4. A pressure detection method for an expansion tank of a closed circulation system according to claim 3, characterized in that according to the first pressure P ₁ Second pressure P ₂ The volume V of the discharged liquid _W Calculating the first gas volume V of the expansion tank under the state to be measured ₁ Comprising determining the first gas volume V by ₁ ，

5. The method for detecting the pressure of the expansion tank of the closed circulation system according to claim 4, wherein the first gas volume V ₁ Standard pressure P ₀ Standard gas volume V ₀ Acquiring a first standard pressure P of the expansion tank under the state to be detected _1t Bag(s)Determining the first standard pressure P by _1t ，

6. The pressure detection method for an expansion tank of a closed circulation system according to any one of claims 1 to 5, further comprising:

Controlling the conduction of a liquid supplementing pipeline of the expansion tank, and injecting liquid with the volume Vw into the expansion tank;

according to the first standard pressure P _1t Said first pressure P ₁ A differential pressure Pw is obtained, wherein pw= |p ₁ -P _1t |；

And supplementing gas or exhausting gas into the expansion tank according to the pressure difference Pw.

7. The pressure detection method for an expansion tank of a closed circulation system according to claim 6, wherein the supplementing gas into the expansion tank or exhausting gas according to the pressure difference Pw comprises:

acquiring an allowable deviation delta P of the expansion tank;

determining whether the pressure difference Pw exceeds the allowable deviation ΔP, where Pw > ΔP, and P ₁ ＞P _1t Under the condition of +delta P, controlling the gas transmission pipeline of the expansion tank to be conducted so as to discharge the gas in the expansion tank until the pressure in the expansion tank reaches Pw less than or equal to delta P; or alternatively

At Pw > ΔP, and P ₁ ＜P _1t And under the condition of delta P, controlling the conduction of a gas transmission pipeline of the expansion tank, and supplementing gas into the expansion tank until the pressure in the expansion tank reaches Pw less than or equal to delta P.

8. The method for detecting the pressure of the expansion tank of the closed circulation system according to claim 7, further comprising, before the step of obtaining the first pressure P1 of the gas in the expansion tank in the state to be measured:

And controlling the liquid supplementing pipeline, the liquid discharging pipeline and the gas conveying pipeline of the expansion tank to be tested to be closed.

9. The method for detecting the pressure of the expansion tank of the closed circulation system according to claim 8, wherein the first temperature T of the gas in the expansion tank in the state to be detected is obtained ₁ Comprising:

acquiring the liquid temperature Tq flowing out of the expansion tank under the state to be detected;

acquiring the ambient temperature Tg of the environment where the expansion tank is located under the state to be detected;

according to the calculation formula T ₁ = (tq+tg)/2, obtaining a first temperature T of the gas in the expansion tank in the state to be measured ₁ 。

10. A pressure detection apparatus for an expansion tank of a closed circulation system, for carrying out the pressure detection method according to claim 1, comprising:

the liquid storage device comprises a liquid discharge pipeline, a liquid storage tank and a first switch valve, wherein two ends of the liquid discharge pipeline are respectively connected with a liquid inlet of the liquid storage tank and a liquid connection port of the expansion tank, and the first switch valve is arranged on the liquid discharge pipeline;

the first temperature detection device is arranged in the environment where the expansion tank is positioned and is used for detecting the environmental temperature of the environment;

The pressure detection device is arranged at the gas connection port of the expansion tank and is used for detecting the first pressure P of the gas in the expansion tank under the state to be detected ₁ And a second pressure P of the gas in the expansion tank in the transitional state ₂ The method comprises the steps of carrying out a first treatment on the surface of the And

the flow detection device is arranged on the liquid discharge pipeline and is used for detecting the volume of liquid flowing out of the expansion tank, and the second temperature detection device is used for detecting the temperature of the liquid flowing out of the expansion tank under the state to be detected.

11. The pressure detecting device for an expansion tank of a closed circulation system according to claim 10, further comprising a controller for controlling the opening or closing of the first switching valve to turn on or off the drain line of the expansion tank under the condition to be measured, and based on the first pressure P ₁ Said second pressure P ₂ Said first temperature T ₁ Volume of liquid discharged V _W The standard pressure P ₀ Said standard volume V ₀ Said standard temperature T ₀ Determining a first standard pressure P of the gas under the state to be detected _1t 。

12. The pressure detection device for an expansion tank of a closed circulation system according to claim 11, wherein the controller is configured to respond to the first pressure P ₁ Second pressure P ₂ And the discharged liquid volume Vw obtains the first gas volume V of the gas to be detected ₁ ；

13. The pressure detection device for an expansion tank of a closed circulation system according to claim 12, wherein the controller determines the first gas volume V by ₁ ，

14. The pressure detecting device for an expansion tank of a closed circulation system according to claim 13, wherein the controller is configured by the following formulaDetermining the first standard pressure P _1t ，

15. The pressure detecting device for an expansion tank of a closed circulation system according to any one of claims 10 to 14, further comprising a fluid supplementing device comprising a fluid supplementing pipe, a fluid supplementing pump and a second switch valve, wherein,

two ends of the liquid supplementing pipeline are respectively connected with an outlet of the liquid storage tank and a liquid connecting port of the expansion tank;

the liquid supplementing pump and the second switch valve are arranged on the liquid supplementing pipeline;

The controller is also used for controlling the second switch valve to be opened, so that a liquid supplementing pipeline of the expansion tank is conducted, and liquid with the volume Vw is injected into the expansion tank.

16. The pressure detection device for an expansion tank of a closed circulation system according to claim 15, further comprising an air supplementing device, wherein the air supplementing device comprises a filter, an air supplementing pump, a third switch valve and an air conveying pipeline, the filter is used for being connected with an air source, two ends of the air conveying pipeline are respectively connected with the air connecting ports of the filter and the expansion tank, and the air supplementing pump and the third switch valve are respectively arranged on the air conveying pipeline;

the controller is further configured to obtain an allowable deviation Δp of the expansion tank;

Determining whether the pressure difference Pw exceeds the allowable deviation ΔP, where Pw > ΔP, and P ₁ ＞P _1t Under the condition of +delta P, the third switch valve is controlled to be opened so as to lead the gas transmission pipeline of the expansion tankLeading the gas in the expansion tank to be discharged until the pressure in the expansion tank reaches Pw less than or equal to delta P; or alternatively

At Pw > ΔP, and P1 < P _1t And under the condition of delta P, controlling the third switch valve to be opened and the air supplementing pump to be started, so that the air transmission pipeline of the expansion tank is conducted, and supplementing air into the expansion tank until the pressure in the expansion tank reaches Pw less than or equal to delta P.

17. The pressure detecting device for an expansion tank of a closed circulation system according to claim 16, wherein the controller is configured to acquire a liquid temperature Tq flowing out of the expansion tank in the state to be measured; acquiring the ambient temperature Tg of the environment where the expansion tank is located under the state to be detected; and obtaining a first temperature T of the gas in the expansion tank under the state to be detected according to a calculation formula T1 = (Tq+Tg)/2 ₁ 。

18. The pressure detecting device for an expansion tank of a closed circulation system according to claim 16, wherein the air supplementing device further comprises a buffer tank connected to the air pipe, the buffer tank being provided between the third switching valve and the air supplementing pump.

19. A wind generating set, characterized by comprising a closed circulation system and a pressure detection device for an expansion tank of the closed circulation system according to any one of claims 10 to 18, wherein a fourth switch valve is arranged at a liquid outlet of the expansion tank, a fifth switch valve is arranged at a gas connection port of the expansion tank, a liquid discharge pipeline and a liquid inlet pipeline of the pressure detection device are detachably connected with the fourth switch valve, and the gas transmission pipeline is detachably connected with the fifth switch valve.